Checklists are cognitive tools that ensure quality, safety and reduce human errors when executing working routines. Besides their popularity in practice, checklists increasingly receive attention from academics, who have even called for a "science of checklists". According to prior studies, mobile checklists are more effective than their paper-based alternatives, but research in this domain is still limited. It focuses on mobile checklists' use and benefits, rather than on their characteristics and design. Our study aims at developing a reference model for conceptualizing mobile checklists. The suggested reference model has been constructed by following design science principles, based on an extensive analysis of paper-based and mobile checklists from the literature and from the practical world. Its main contribution is a shared understanding of the domain knowledge between users and developers, which helps to communicate innovative ideas about mobile checklist applications.